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Biomedical subjects

A Spierer

Publications and source records attributed to A Spierer.

At least 19 recordsLinked to original sources
PubMed1996

Position-effect variegation in Drosophila depends on dose of the gene encoding the E2F transcriptional activator and cell cycle regulator.

A dominant mutation due to the insertion of a P-element at 93E on the third chromosome of Drosophila melanogaster enhances position-effect variegation. The corresponding gene was cloned by transposon tagging and the sequence of the transcript revealed that it corresponds to the gene encoding the transcriptional activator and cell cycle regulator dE2F. The transposon-tagged allele is homozygous viable, and the insertion of the transposon in an intron correlates with a strong reduction in the amount of transcript. A homozygous lethal null allele was found to behave as a strong enhancer when heterozygous. Overexpression of the gene in transgenic flies has the opposite effect of suppressing variegation. A link is established here, and discussed, between the dose of a transcriptional activator, which controls the cell cycle, and epigenetic silencing of chromosomal domains in Drosophila.

Amino Acid Sequence↗
PubMed1995

Convergence insufficiency secondary to subdural hematoma.

PURPOSE/METHODS: Symptomatic convergence insufficiency developed in a 56-year-old man after he sustained head trauma and developed subdural hematoma. RESULTS/CONCLUSION: All symptoms resolved after surgical evacuation of the subdural hematoma. Convergence insufficiency developing after head trauma could be the result of a subdural hematoma.

Brain Injuries↗
PubMed1994

[Secondary glaucoma after congenital cataract surgery].

In a retrospective study, the incidence of secondary glaucoma after congenital cataract extraction was evaluated. Causes of this type of secondary glaucoma include peripheral anterior adhesions which obstruct the anterior chamber angle and prevent normal outflow of aqueous humor, pupillary block, intraocular hemorrhage, and chronic uveitis, among others. During the past 12 years 41 children (57 eyes) were operated for congenital cataract. Secondary glaucoma was found in a 1-month-old boy and a 1-month-old girl (5.3%; 3 eyes). Follow-up in most patients was less than 5 years. A similar incidence of secondary glaucoma has been reported by others. In spite of the low incidence of this complication, secondary glaucoma should be excluded during routine follow-up of these children.

Cataract↗
PubMed1993

Adenovirus type 8 conjunctivitis outbreak in a neonatal intensive care unit.

An outbreak of adenovirus type 8 conjunctivitis occurred in seven premature infants who had undergone ophthalmological examination four to seven days previously. Three of the affected infants, treated with steroids because of bronchopulmonary dysplasia, showed systemic manifestations and deterioration of their respiratory disease. Second and third waves affected nine staff and 12 family members.

Adenovirus Infections, Human↗
PubMed1993

Corneal changes in chondrodysplasia punctata syndrome.

A child with chondrodysplasia punctata syndrome is presented. In addition to the bilateral congenital cataracts that have been described previously in this syndrome, this child had bilateral corneal punctate erosions. These corneal abnormalities, which to the best of our knowledge have not been described in this syndrome before, persisted for at least three years.

Abnormalities, Multiple↗
PubMed1992

Secondary cataract in infants after extracapsular cataract extraction and anterior vitrectomy.

Two infants developed secondary cataract after undergoing extracapsular cataract extraction (ECCE), posterior chamber intraocular lens (IOL) implantation, posterior capsulectomy, and anterior vitrectomy. A similar complication developed in a third child, who had undergone ECCE and posterior capsulotomy. The secondary cataracts developed in these patients from 3 to 12 weeks after the primary operation. In infants, unlike adults, posterior capsulectomy and anterior vitrectomy after ECCE do not seem always to prevent secondary cataracts. In infants, the complication may be related to IOL implantation.

Anterior Eye Segment↗
PubMed1991

The role of increased intraocular pressure on upgaze in the assessment of Graves ophthalmopathy.

The significance of the increase in intraocular pressure (IOP) on upgaze in the diagnosis of Graves ophthalmopathy and its normal range are controversial. The authors measured the increase in IOP on upgaze in 69 hyperthyroid patients with Graves disease, diagnosed at 1 month to 15 years previously, to assess their clinical, laboratory, and ophthalmic state. Ninety-seven healthy subjects served as controls. The distribution of increase in IOP on upgaze values in 46 patients with noninfiltrative ophthalmopathy (classes 0 to 1) was the same as in the control group. The 23 patients with infiltrative ophthalmopathy (classes 2 to 4) had increased frequency of higher increases in IOP on upgaze values compared with the other two groups. However, because of considerable overlap, increase in IOP on upgaze was not discriminatory between the groups. Increase in IOP on upgaze correlated positively with the severity of exophthalmos. There was no correlation among age, sex, time since diagnosis, thyroid functional state, and drug therapy. The authors conclude that an increase in IOP on upgaze is a normal finding augmented by Graves infiltrative ophthalmopathy. It has no diagnostic advantage over the simple clinical signs of ophthalmopathy.

Adolescent↗
PubMed1991

Evaluation of accommotrac biofeedback training for myopia control.

A new treatment for myopia, biofeedback training for control of accommodation, has been proposed and developed over the past decade. Various reports in the literature show marked inconsistencies in the results of such treatment. A double-masked study with experimental and control groups of 15 subjects each was designed to obtain a definitive answer concerning the efficacy of this method. The parameters evaluated were visual acuity, cycloplegic and noncycloplegic retinoscopy, subjective refraction, amplitude of accommodation, and flexibility of accommodation. In all categories no significant difference was found between the control and experimental subjects. The consequences of these findings are discussed as to the benefit of treatments using this method and avenues to explore in future studies.

Accommodation, Ocular↗
PubMed1991

Etiology of reduced visual acuity in congenital nystagmus.

A study was undertaken to identify the etiologic factor of reduced visual acuity in congenital nystagmus. Fourteen children with congenital nystagmus and reduced visual acuity were examined, using a modified "E" game test. Their success rate in identifying vertical lines was compared with their success rate in identifying horizontal lines. The children identified both vertical and horizontal lines with a similar rate of success. These results may indicate that poor vision in congenital nystagmus patients is partly the result of amblyopia.

Amblyopia↗
PubMed1990

Dependence of position-effect variegation in Drosophila on dose of a gene encoding an unusual zinc-finger protein.

Position-effect variegation is the inactivation in some cells of a gene translocated next to heterochromatin, the region of the chromosome that is permanently condensed. The number of copies of the Drosophila gene Suvar(3)7 is a dose-limiting factor in this phenomenon, and seems from its sequence that it encodes a protein with five widely spaced zinc-fingers. This novel arrangement of zinc-fingers could help in packaging the chromatin fibre into heterochromatin, and also reflect a novel method of controlling the expression from DNA domains.

Amino Acid Sequence↗
PubMed1989

Outpatient topical use of povidone-iodine in preparing the eye for surgery.

Povidone-iodine 5% solution placed on the eye immediately before ophthalmic surgery within the preoperative preparation significantly reduces the conjunctival bacterial flora. In 40 patients undergoing ophthalmic surgery, the authors compared the outpatient use of povidone-iodine for 3 days before surgery with a 3-day course of a combination antibiotic ophthalmic solution (Neosporin) placed on the other eye. All patients also received topical povidone-iodine on the operating table directly preceding surgery. Cultures taken just before preparation of the operative field showed a similar reduction of bacteria by each regimen. Cultures taken after preparation but before commencement of surgery showed a further reduction for both regimens, but more for eyes previously treated with the antibiotic (P less than 0.02). To minimize the conjunctival bacterial flora before surgery, the authors continue to recommend instillation of a broad-spectrum antibiotic for 3 days before surgery, followed by application of povidone-iodine solution to the eye immediately before surgery within the preoperative preparation.

Ambulatory Care↗
PubMed1988

Binocular function after surgical alignment of infantile esotropia.

Fifty patients with infantile esotropia, randomly selected, and operated at different ages, were evaluated in regard to their final alignment and sensory results. Comparisons of the age groups above and below 36 months of age, did not reveal a difference in their postoperative alignment. Sensory testing showed that a lower percentage of binocularity was found in patients operated on and aligned after 36 months of age. Most patients showed evidence of binocularity in only one of the sensory tests that were used in this study.

Age Factors↗